In this video from Motley Fool Live, recorded on March 15, Fool.com contributors Brian Orelli and Keith Speights discuss the final analysis of data from clinical trials testing Novavax's (NASDAQ:NVAX) coronavirus vaccine. The data compare well to the mRNA-based vaccines when just looking at the original strain of the virus. And there's some evidence that Novavax's vaccine is also protecting against the U.K. variant, and to a lesser extent against the South African variant.

Brian Orelli: Then Novavax released final analysis of phase 3 data from the U.K. study and phase 2b data from the South Africa study. In the U.K. study, the efficacy ended up being 96.4% against the original virus strain, and then 86.3% against the U.K. variant. It's a post-hoc analysis, but the data against the original strain is actually slightly better than [with] both Moderna (NASDAQ:MRNA) and Pfizer (NYSE:PFE) and BioNTech (NASDAQ:BNTX).

In the South African study, the overall efficacy was 48.6%, or 55.4% efficacy when you just look at HIV-negative people -- definitely not protecting against the South African strain as well as it does against the U.S., the original strain, or the U.K. strain.

One interesting data point that I found was in patients who got the placebo. They looked at those patients, and the illness rate was 7.9% for people who didn't have antibodies to the coronavirus going into the study. Then for patients who did have antibodies at the start of the study and then ended up getting placebo, the rate was 4.4%, so 7.9% for people who didn't have the antibodies vs. 4.4% for people who did have the antibodies. Seems like their original coronavirus is protecting against the South African variant, although certainly not 100%. Any thoughts on the data?

Keith Speights: Yeah, I'm like you: I'm fascinated by that very early data about...that maybe having antibodies to the original strain of coronavirus could give you that protection against these new strains. I will be interested to see further studies as they come out, to see if that pans out.

I thought, arguably, the most important results announced by Novavax, though, was that 100% protection against severe disease. I mean, that's absolutely great news and that's what you want to see -- I mean, 100% protection against the severe cases of COVID-19. That means fewer people dying, fewer people having to go to the hospital. That was a great result.

There's always uncertainty with the regulatory process, whether it's getting emergency use authorization or ultimate approval. But I would say, based on this data, Novavax has about as close [to] a slam dunk for authorization as you're going to get, at least in the U.K. for right now, because this is all based on U.K. data and they will seek emergency use authorization in the United Kingdom first. But I think it's looking really good for Novavax right now.

But there's kind of a "good news, bad news" story, with significantly lower efficacy with the South African variant. And in particular, the bad news, obviously, is that the efficacy is a whole lot lower. If that variant becomes more prevalent, then Novavax's vaccine will provide nearly as much protection and might be at a competitive disadvantage if -- and this is a big if -- if another drugmaker launches a vaccine that is more effective.

But there's good news too, potentially, because Novavax is itself testing a booster dose targeting the strain, and it's also developing stand-alone and bivalent vaccines that target these new variants. So if Novavax is successful with those efforts, that could potentially pave the way for strong recurring revenue beyond 2021 and after the pandemic is over. I think it really is a "good news, bad news" situation with this variant.

Orelli: They're almost at a disadvantage because they tested in South Africa, and others haven't, necessarily. It looks bad, but you don't really know what to compare it to.

Speights: Exactly. I mean, it's very possible that Novavax's vaccine could be more effective against the South African variant; we just don't have similar data from the other vaccine makers. You are right.